Boiler and furnace wall support



G. J. SCHOESSOW BOILER AND FURNACE WALL SUPPORT Jan. 29', I952 6 Sheets-Sheet 1 Filed March 14, 1946 INVENTOR Glen J Schoessow ATTO RNEY Jan, 29, 1952 Filed March 14, 1946 6 Sheets-Sheet 2 J 2 i I INVENTOR Gigi; J Schoessofi ATTORNEY G. J. SCHOESSOW 2,583,599

BOILER AND FURNACE WALL SUPPORT Jan. 29, 1952 G. J. SCHOESSOW BOILER AND FURNACE WALL SUPPORT 6 Sheets-Sheet 3 Filed March 14, 1946 INVENTOR 5c/zoessow ATTORNEY G/en J G- J' SCHOESSOW BOILER AND FURNACE WALL SUPPORT Jan. 29, 1952 6 Sheets-Sheet 5 Filed March 14, 1946 INVENTOR Glen J Sciz oessow ATTORNEY 1952 G. J. SCHOESSOW BOILER AND FURNACE WALL SUPPORT 6 Sheets-Sheet 6 Filed March 14, 1946 I/IIIIIIIIIIIIIIIA INVENOR J5c/70ess0n G/en ATTORNEY Patented Jan. 29, 1952 2,583,599 BOILER AND FURNACE WALL SUPPORT Glen J. Schoessow,

The Babcock &

Barberton, Ohio, assignor to Wilcox Company, Rockleigh, N. J., a corporation of New Jersey Application March 14, 1946, Serial No. 654,239

13 Claims. (Cl. 122--235) The invention herein disclosed relates in general to the construction of vapor generating units, andmore especially to the supporting structure of steam boilers and furnaces having a fluid cooled combustion chamber laterally adjoining the convection heated boiler surfaces.

An object of my invention is the provision of a support allowing freedom of expansion of essential boiler or furnace parts due to temperature variations.

Another object is the provision of a support arranged to direct all expansive movement from a single restricted location or zone.

An additional object relates to the vertical support of a vertically extended fluid cooled furnace from an intermediate level.

Other objects relate to the lateral support of fluid cooled walls at a given level together with the vertical support of the walls from approximately the same level.

Another object of this invention is the provision of a structural support for a boiler and integral furnace pressure parts which is simple ,in construction and economical in cost.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which I'have illustrated and described preferred embodiments of my invention.

Of the drawings:

Fig. 1 is a front elevation of a steam boiler setting constituting an embodimentof my invention;

Fig. 2 is a sectional front elevation of the boiler shown in Fig. .1 taken on the line 2-4 of Fig. 4;

Fig. 3 is aplan section of the boilerfurnace taken on line 3-4 of Fig. 2;

Fig. 41s a plan sectionsimilar to Fig. 3; taken on line 4-4 of Fig. 2;

Fig. 5 is a vertical section taken on line 5--5 of Fig. 4;

Fig. 6 is a plan view, partly in section, taken on line 6--6 of Fig. 5;

Figs. 7 and 8 are vertical sections taken on lines 1--1 and 8-8, respectively, of Fig. 4;

Fig. 9 is a plan section taken on line 9-9 of Fig. 8;

Fig. 10 is a vertical section taken on line Ill-I 0 of F18. 3.

Fig. 11 is a vertical section taken on line l 1- of Fig. 10;

Fig. 12 is afragmentary sideelevation taken on line 12-42 of Fig. 3;

Fig. 13 is an end view, on line Ill-l3 ofFig. 12;

Fig. 14 is aplan; section of Fig. 13,

Fig. 15 iswa fragmentary front elevation, in section. taken on line l5--|5 of Fig. 3;

Fig. .16- is a fragmentary sideelevation taken along line 16-46 of Fig.3;

Fig. 17 is-an end view. partly in section,taken along line l1-|1 of Fig. 16; and

Fig. 18 is a vertical section taken along line l8--|8 of Fig. 3.

In the drawings, and referring first to Figs. 1-4, my invention is shown in connection with a vapor generating unit 10 of the integral furnace type having a setting of substantially rectangular. horizontal cross section as defined by uprightfront and rear walls I2 and [3, respectively, together with oppositely disposed upright side walls M and I5, and an upper enclosing wall or roof 16. The space within the setting is divided by an upright interior partition wall I! to provide a boiler tube space It laterally adjoining the upper portion of a furnace or combustion chamber 19 extending downwardlybelow the level of tube space I8, the lower portion of the chamber being formed as an ash hopper 2| having inclined side wall portions 23 and converging downwardly toward a rectangular throat passage .25 discharging into an ash pit.26 therebelow. In the constructiondisclosed, the inclined hopper walls 23.,and are essentially lower extensions of the upright setting wall l4 and partition wall I! respectivelywhich thus constitute the side walls of combustion chamber l9. One or more burners 21 of; a type suitable for thefuel to be burned are installed in association with the burner opening or openings .28 in frontfurnace wall l2, for example, to-provide a source of heating gases. Air for combustion is supplied to the burner or burners through a windbox 29 to which air underpressure is. supplied by the'customary forced draft fan (not shown).

The partitionwall l1 extends from the front, orburner furnace wall H to a location spaced from the rear wall l3 whereby a passage 3| is provided for heating gases flowing from the. combustion chamber I9 into the tube space I 8. Transverse. upright baflles .32 and 34 divide the tube space into serially connected gas passes 35, 36, and 31 through which a substantially horizontal partly in section, taken taken on line 14-14 partly the drums beingconnected by 'a main 'bank of upright boiler tubes 42 disposed within tube space is between front and rear walls l2 and I3, such tubes being arranged for example in parallel rows extending longitudinally of drums 39 and ll, and including tubes of different diameters and spacingsindifferentgas passes.

Each of the setting walls l2, l3, l4, and I5, and partition wall ll, comprises at least one row of upright fluid cooling tubes lZa, l3a, Hid,

I511, and H0, respectively, suitably connected to drums 39 and M, to provide natural circulation flow paths in parallel with the boiler bank 42.

In some instances the connection of-the wall tubes to drums 39 and il may be direct,as in the case of'boiler tubes 42 and wall tubes I21), I31), and led in the regionof tube space [8, whereas in 'other instances'theconneotions to the drums may be indirect and include known arrangements of headers, make-up tubes and riser tubes as shown. For example, inopposite side Walls of the combustion chamber IS, the tubes Ma and lldare connected at their lower ends to headers 30 to which water is supplied from the lower drum 4| through downcomer means in the form of tubes 43and l l. In rear wall l3, the tubes Isa are connected at their lower ends to header 5K! to which water is supplied from the lower drum M through downcomer means in "the form of tubes 52. The upper ends of wall tubes 1311 are connected to header 53 from which riser tube 55 extend to the upper drum 39. Similar connections, not shown, are made for tubes 12a in front wall l2. It will be noted from Fig. 4 that the tubes-associated with Walls.l3 and I in certain higher-temperature zones are more closely spaced than those associated with walls l2 and I5 in lower temperature zones, tubes l3a and Ma being arranged in their respective rows at center-to-center spacings substantially equal to their diameters, and thereby providing an essentially closed wall structure. Where the tubes are spaced apart in the row a space closing refractory wall is provided with the-plane-of its furnace face tangent to the outer circumference of the tubes.

In hopper wall 2 3, and in partition wall I! which forms an upper extension thereof, the tubes I19 are arranged ina single row at center to-center spacings substantially equal to their diameters as in the case of rear wall tubes [3a and side wall tubes I la. Tubes I are tied together and to lower drum 4| by means of tie bar channel .45 to which each tube is welded top and bottom as at 46, plates 41 welded at intervals to the channel, and plates. 48 welded to the drum "and to which the plates 47. are secured by suitable fastener mean 49. 5 The portions of tubes- I'll! above'tie bar 45 may be regarded as comprisingtwo groups Ila and 'l'lb asdetermined by their form and arrangement, in group l'l'a the tubes extending upwardly in a single longitudinal row to form partition wall [1 including an inclined gas defleeting portion 5|, the spacing of tube portions lla being the same as the spacing of tubes H0 in hopper wjau 2s, and in group lib the tubes extending upwar'dl'yinspaced relation in a plu 4 rality of longitudinal rows across the entrance 3! to gas pass 35.

The entire weight of the boiler including its furnace is carried by a structural frame or foundation support of rectangular horizontal arrangement and comprising, for example, horizontal front, rear, and side frame members 5:1, 55, and 51, 58,'respectively, tied into columns as and GI along opposite sides, the-frame members 5%, 56 and 58 presenting upper support surfaces in a common horizontal plane. The boiler mud drum 4| is bottom supported, being carried in saddles 62 and. 63 supported on a side member 5'! which with columnsiQ is positioned below drum M on a vertical centerline therewith, the saddle 62 being of a fixed type maintaining the drum stationary adjacent burner wall i2 while saddle 63 is of roller supported type permitting longitudinaldrum movement relative to its fixed stationary front end portion carried by saddle 62. The furnace walls are verticallysupported, at an elevation corresponding substantially to the center line level of the bottom supported boiler mud drum ti, so that allexpansionof theentire boiler unit is from that one elevation. Lateral support of the furnace walls is afforded by tie bar and buckstay units 6 and 65 which encompass the furnace, one at the mud drum 'leveland one at a level intermediate the upper and lower boiler drums as indicated in Fig. 1.

In front wall l2, a frame 6'! is formed about burner openings 28 comprisingupright channel members 658 extending between and suitably secured to front beam 54 and upper'lateral support unit 55. The lower support unit 64, although formed in sections tied and/64b at opposite sides of frame 6'1, i nevertheless an essentially continuous structure by reason of its attachment as by angles 89 to the upright frame members 63.

At the mud drum level, the lateral support unit 64 comprises tie bars H and F2 for front wall l2, and tie bars 73 and M for walls l3 and l4,.respectively, each tie bar being secured to each wall tube l2a, ltd, or led in the associated wall, either direct as in walls l3 and M, or through channelsection spacers 15' as in wall l2, the tie bars for adjoining walls being welded together at the corners as at it. Inrear wall it and in side wall M, the attachmentof tie bars to tubes 13a and Ma is suitably made by welding. In front wall i2 where channel spacers 15 are indicated, tie bar 12 and tubes i211 may, for example, be tied together by means of stud and nut connections as in the embodiment hereinafter described.

The connection of the tubes of wall I 5 is correspondingly made with the use of 'chan'nel'spacers. Refractory material as indicated is positioned outwardly of the plane of the outer faces of the tubes and between the spacer channel sections. Buckstays it, it, 8i] and 81 for the respective walls are secured at intervals therealong to the corresponding tie bars by tie plates 32- and 83 and, for adjoining walls, are interconnected at the corners by horizontally extending gusset plates 84 welded as at 85 top and bottom to the adjacent tie bars l2, l3 and ll. A suitable assembly of buckstay, tie bar and tube is detailed in Fig. 18 where a buckstayfie for rear wall l3, for example, is shown as comprising upper and lower channel members arranged .back-to-beiok and secured. by bolt 89 to a tie plate'ilz therebetween having its inner edge Welded as atv Hi to the upper edge of tie bar '13, the tie plate having a slotted bolt hole 92 therein parallel to the associated Wall [3 to permit relative. longitudinal movement between the. wall and. buckstay.

Each corner plate. 84 is provided with two rows: otslotted bolt holes 94. and 95 at rightangles to each other for receiving bolts orother fasteners 94a and 9511 by which the plate is connected to the respective buckstays, the. bolt holes in. the buckstays being circular and providing normal clear-. ance for the bolts. At thejuncture offrontwall I2 with side wall I4, for example, the slotted. bolt holes 94 are elongated parallel to tie. bar "I2 in front wall I2, while. bolts 94a are. in alignment with the centerline of tie bar 14 in side. wall I4. Similarly, slotted bolt holes 95: are. elongated parallel to tie bar 14 in sidewall I 4, while bolts 95a are in alignment with the centerline of tie bar It in front wall I2. At the juncture. of walls I3 and I4, the bolt holes 94, 95.and boltso94a, 95a are in similar relation with respect to tie. bars 13 and '14.

Tie bars II and I3 in front and rear walls I2 and I3, together with the corresponding buckstays I8 and 80, are each tied into mud drum 4| as detailed in Figs. 10 and 11- for front wall I2.

Angle plate 96 is welded to the drum as shown,

and tie bar II, for example, is secured to the vertical leg of the plate as by bolts 9'1. Buckstay 18, comprising channel members arranged back-to-back, is secured as by bolts 98 to a tie plate 99 therebetween having its inner edge welded to the upper edge of tie bar II.

The furnace walls- I2, I3 and I4 are vertically supported by pivoted columns IDI extending from foundation frame members 54, 56, and 58 to the lower tie barand buckstay unit 64 with which the columns have pin connections permitting expansive movement of the walls transversely of the tube lengths therein without inducing a bending reaction in the vertical tube length portions.

Figs. 1-2, 13 and 14 illustrate two such columns IIlI as installed in connection with side wall I4 between foundation frame member 58 and theside wall tie bar I4. Each column is of I-beam crosssection having itsbottom end connected by a pin I02 to upstanding flanges of angles I03 mounted at opposite sides of its web Mon at suitabletooting or base plate I95. At the upper end of column I III a portion of flange N16 is cut away to receive plates I01: secured as by welding to opposite sides of the column webv and extending to.- ward. the row of tubes Ma where they are con-. nected' by pin [68. to. horizontally spacedv plates I113 welded to tie bar 1.41 throughout its width, and suitably to tie plate 8.3.. at its upper end. When located adjacent burner wall I2 as indicated, where longitudinal wall displacement is the least, the two columns IIII may be connected, by. a. div agonal brace. II 2 for increased wallrigiditvthe brace being framed into the vertical columns IIII nd aving its web 3 Wel ed thereto- E ss. 1. and 17 show columns IQI as previously described b t' it u the dia onal ra n asusedsato ho si o s n Wa M. or n. ther. walls. or at lo ationsas in front wall IZwhere a single column I III is indicated.

The lateral support unit 64, and th pivoted support connections to tie bar components of that unit are at substantially the same. level as. the center lineof the lower drum of the boiler proper, and provision is thus made for all expansion and contraction to take place from sucha predetermined level and from the-fiXed; end of that drum.

This is accomplished through the double pinningof the columns in, their connections to the supp r in t l work. and the. ie: a s h pivo ed. colum swill tip or chan e their upri ht ali nment with changesin he. amount of move. meat or the oint of wall attachment. For the. rear wall I 3 the slight movement will be angularly about the axes. of, the low r pivo d c nnections, while the case of the side wall I4, themovement Off the upper pivoted connection, will be both outw rd: an in a d rec ion p rallel to the plane of the wall, To provide for the latter movement the pinconnec i s are provi ed with ome clearance between pins and holes.

The in type of connections for the column have been selected as a ype well adapted to fab.- rication and erection, but other specific pivot type constructions permitting similar relative movement, of the column relative to itssupportins base and relative to the member supportedat; the top of the column, as for example ball and socket connections, are within the scope of the inventio The tie bar and; buckstay level; between drums 39 and 4|: is of the same general construction as unit 64 except that it is continuous about the entire upper crosssection of the setting and is supported solely by tubes adjacent. the walls.

In front wall I2, because of the smaller thick-. noss of refractory III adjacent tube space l8, the; channel spacers I I8 may be of smaller size requiring tie bars IIS and I2I to be ofiset and connected as at I23. In rear wall I3, the tie bars I24 and I25 are also offset and connected as at I25, in his Wall tie bar I24. being secured to tubes I312 with spacers I I8, therebetween, while tie bar I25 is secured to tubes I3a direct. in side wall I4 tie bar I25 is secured direct to tubes Ma, whereas in the opposite side wall I5, tie bar I27 is secured to tubes I 5a with spacers I I8 therebetween.

Buckstays I32, I33, I34, and I for walls I2, I3, I4, and I5 respectively are each formed of channel members arranged back-to-back. and tied in to the respective tie bars by tie, clips I36 and I 31 of angular formation as in Figs. 5-7, each clip having a slotted bolt hole 92 therein to, allow for difierential expansive movementbetween the associated tie barsandbuckstays. R8?- ferring to Figs. 5 and; 6. Where channel spacers are employed, the horizontal leg of clip I35 ex.-

unit at the upper tends between the channels. of buckstay I 33. to.

which it is secured by bolt I38, while the vertical leg extends upwardly against theouter side of tie bar I24 to. which it is secured by threaded studs I39. welded to tube I32) and fitted with nuts I41, the studs extending. through channel spacers H8, and a pipe spacer I42 being interposed between clip I36 and spacer III! to bridge the gap above tie bar I24. Referring to Fig. 7 where channelspacers are'omitted, tie bar-I25 is bolted direct to the tube, and pipe spacer I42 is inserted between clip I31 and tube I32). At locations along thevarious walls where noclip members are indicated, the same constructions shown in.Figs. 547 may be. employed, merely by omitting clip I36 or I31.

Bhe tie bars in adjoining walls arewelded'together at all four corners 1.6 as in the construcionat tw c r e s o t e barsaat themud drum e l... Buoks a s adj inin wallsare also intor onnect d at he four c r crs. n the. manner hown n F or t ov rn s. with. olt holes Qtn olts Ma, 95a. arra das prev ously de cr b d. for a tachment to, gusset plates 84 bioha ew lded to thetie bars at 85- T e ba I45 a e inc uded inthe assembly of arcades partition wall [1 as indicated in Figs. 4, 8 and 9, such bars extending transversely of tubes Ila suitably in overlapping sections at adjacent levels; intermediate the height of the partition, as indicated in Fig. 8. Tube i'ic nearest the front wall tie bar i2! is tied thereto by stud and nut connections as in Fig. 5, and all tubes of the partition including tube Vic are tied to bars 145 in a similar manner with studs M6 and nuts I41 as indicated. Each tie bar M is of corrugated cross section providing alternate ridges and grooves for close engagement with the tube surfaces. The bar or bar section I45 nearest front wall I? is extended as at M8 for attachment by bolts I49 to channel spacer H5.

' The described supporting provisions for the walls and pressure parts of a vapor generating unit are of simple and relatively low cost construction, requiring substantially less steelwork than prior commercial constructions for this purpose, and yet'more effectively providing the necessary freedom of movement of the supported parts due to thermal expansion and contraction and thus avoiding distortion and possible rupture of the parts so stressed. In one type of steam boiler, for example, the amount of supporting steelwork was reduced approximately 50%.

While in accordance with the provisions of the statutes I have illustrated and described herein the best'forms of my invention now known to me those skilled in the art will understand that changes may be made in the form of the apparatus disclosed without departing from the spirit of the invention covered by my claims, and that certain features of my invention may sometimes be used to advantage without a corresponding use of other features.

I claim:

1. A vapor generating unit comprising a vertically arranged bank of generating tubes, upper and lower horizontally extending drums connected to said tubes, means for bottom-supporting said drums and tube bank, a laterally offset furnace combustion chamber at one side of said tube bank and having upright boundary walls lined with upright generating tubes, said walls including a pair of opposing walls extending substantially parallel to said drums and having the tubes thereof extending to and connected to said upper drum, said opposing walls and the wall tubes thereof having integral inclined lower portions converging downwardly at elevations below said lower drum, and means for vertically supporting said boundary walls including weight support means engaging said opposing wall tubes above said inclined lower portions at approximately the elevation of said lower drum, said weight support means including means securing the tubes of one of said opposing walls to said bottom-supported lower drum.

2. A furnace having a boundary wall including a row of upright fluid heating tubes, horizontally arranged bar means secured to and supported on said tubes and tying the tubes in predetermined center-to-center relation at a level intermediate their height, upright weight support means having an end portion pivotally connected to said tying bar means, a load carrying structure positioned externally'of said wall and adjacent thereto, and a pivoted connection between the opposite end portion of said support means and said structure, said pivotal connections providing parallel pivotal axes arranged parallel to said row of tubes to permit movement of said tubes in a direction normal to said wall.

3. A furnace having a boundary wall includin a row of upright fluid heating tubes, horizontally arranged bar means secured to and supported on said tubes and tying the tubes in predetermined center-to-center relation at a level intermediate their height, upright weight support means having an upper end portion pivotally connected to said tying bar means, a load carrying structure positioned externally of said wall and adjacent thereto, and a pivoted connection between a lower end portion of said support means and said structure, said pivotal connection providing parallel pivotal axes arranged transversely of said tubes to permit movement of said tubes in a planenormal to said wall.

4. A furnace having vertical boundary walls defining a combustion chamber of substantially rectangular horizontalcross-section, a row of vertical fluid heating tubes extending along the inner side of each of said walls, a horizontally arranged tie bar connected to each row of tubes, a gusset plate fixedly secured to the adjoining ends of tie bars in adjoining walls, a horizontally arranged buckstay extending along the outer side of each'of said adjoining walls and having a web portion overlapping said gusset plate, means vertically supporting each of said buckstays on tubes of the corresponding wall comprising a weight supporting connection between each tie bar and the corresponding buckstay and permitting relative longitudinal movement therebetween, and means forming expansible connections between the ends of adjoining buckstays and said gusset plate comprising connecting members extending through registering holes insaid gusset plate and overlapping web portions.

5. A furnace having vertical boundary walls defining a combustion chamber of substantially rectangular horizontal cross-section, a row of vertical fluid heating tubes extending along the inner side of each of said walls, a horizontally arranged tie bar connected to each row of tubes, a gusset plate fixedly secured to the adjoining ends of tie bars in adjoining walls, a horizontally arranged buckstay extending along the outer side of each of said adjoining walls, means vertically supporting each of said buckstays on tubes of the corresponding wall comprising a weight supporting connection between each tie bar and the corresponding buckstay and permitting relative longitudinal 'movement therebetween, means forming expansible connections between the ends of adjoining buckstays and said gusset plate, and means vertically supporting said walls comprising longitudinally spaced upright .supports pivotally connected to each of said tie bars about a common horizontal axis parallel thereto.

6. A furnace wall including a row of vertically extending fluid heating tubes, a horizontally extending tie bar Welded to the outer sides of said tubes, a buckstay laterally supporting said wall and comprising a pair of horizontally arranged spaced channel bars positioned with their web portions back to back, means for supporting said buckstay on said tubes comprising a plate positioned between said channel bars and connected to the web portions thereof, said plate having a portion projecting inwardly beyond said channel bars and secured to said tie bar, and means for vertically supporting said wall inclusive of said buckstay comprising weight support means having a pivoted connection with said tie bar.

'7. In a vapor generating unit having an upper and a lower drum arranged in substantially vertical alignment and connected by tubes, means -mote from said I comprising a row of upright fluid cooling tubes 9 for bottom-supporting said drums and saidtub es, a furnacecombustion chamber arranged laterally of and directly adjacent the space containing said tubes and having an inner and an outer upright wall respectively adjacent to and relower .rum, each of said walls having circulatory connections with said drums, said inner wall including tubes extending to and connected to said upper drum, said walls and the 4 tubes thereof having substantially vertical portions at substantially the elevation of saidlower drum and having integral inclined lower portions converging downwardly at elevations below said lower drum, and means for vertically supporting said walls comprising weight support means engaging said vertical tube portions in each of said walls at an elevation corresponding substantially to the elevation of said lower drums,

inclusive of means maintaining the tubes of said inner wall stationary with respect to said lower drum in the region of weight support means in engagement with said inner wall tubes.

8. A furnace having a pair of adjoining upright walls defining a corner of a furnace com bustion chamber a row of vertically arranged fluid heating tubes extending along each of said walls adjacent the inner side thereof, a horizontally arranged tie bar connected to each row of tubes, horizontally arranged buckstays extending respectively along the outer sides of said walls and formed with horizontally extending web portions adjacent said corner, means including said tie bars vertically supporting said buckstays on tubes of the respective walls, a corner plate overlapping said web portions and fixedly secured to the tie bars in said walls, and means forming horizontally expansible connections between said corner plate and said web portions comprising members extending through registering holes in said overlapping corner plate and Web portions, said holes in web portions of the respective buckstays being aligned in sets with tie bars in the respective adjoining walls, and the holes in said corner plate being arranged in sets each registering with a set of said aligned holes and being elongated transversely of the direction of said alignment.

9. A vapor generating unit comprising a vertically arranged bank of generating tubes, an up per and a lower horizontally extending drum connected to said tubes, means for bottom-supporting said lower drum and through said tube bank vertically supporting said upper drum, a laterally offset furnace combustion chamber at one side of said tube bank and having vertical boundary walls lined with vertical generating tubes discharging to said upper drum, means for vertically supporting said wall tubes intermediate the lengths thereof at approximatelythe elevation of said lower drum, said wall of said furnace chamber and pivoted support connections between said structure and tubes of the respective walls, and downcomer means connecting said lower drum to the lower ends of said wall tubes.

10. A vapor generating unit comprising a vertically arranged bank of generating tubes, an upper and a lower horizontally extending drum connected to said tubes at upper and lower ends thereof, means for bottom-supporting said lower drum and through said tube bank vertically supporting said upper drum, a laterally offset furnace combustion chamber at one side of said tube bank and having vertical boundary walls lined with vertical generating tubes, means for vertically tube supporting means including a stationary structure externally supporting said wall tubes at approximately. the elevation of the center line of said lower drum including upright column members externally of and adjacent to said wall tubes, pivoted support connections between said column members and said wall tubes, and means extending transversely of said wall tubes andconnected thereto and to said lower drum for laterally supporting said walls at approximately said elevation of bottom support.

11. A vapor generating unit comprising a vertically arranged bank of generating tubes, an upper and a lower horizontally extending drum connected as, said tubes at upper and lower ends thereof, means for bottom-supporting said lower drum and through said tube bank vertically supporting said upper drum. a laterally offset furnace combustion chamber at one side of said tube bank and having vertical boundary walls disposed in separate planes and lined with vertical generating wall tubes discharging to said upper drum, means for laterally supporting said walls at a substantially common elevation, means for vertically supporting said walls including upright column members externally of and adja cent to said wall tubes, and means including pivoted vertical support members connecting said column members to said wall tubes at approximately said elevation of lateral support.

12. A vapor generating unit comprising a bank of upright generating tubes, an upper and a lower horizontally extending drum to which opposite ends of said tubes are connected, means for bottom-supporting said lower drum and through said tube bank providing vertical support for said upper drum, a furnace combustion chamber arranged laterally of and adjacent said tube bank and having an inner and an outer upright wall paralleling said lower drum and arranged respectively adjacent to and remote from said lower drum, each of said walls comprising upright fluid conducting tubes extending to elevations above said lower drum and having circulatory connections with said drums, said walls and the tubes thereof having substantially vertical portions at substantially the elevation of said lower drum and having integral inclined lower portions converging downwardly at elevations below said lower drum, and means for vertically supporting said walls comprising weight support means engaging said vertical tube portions in each of said walls while maintaining said vertical portions of tubes of said inner wall stationary with respect to said lower drum.

13. A vapor generating unit comprising a vertically arranged bank of generating tubes, an upper and a lower horizontally extending drum connected to said tubes at upper and lower ends thereof, means for bottom-supporting said lower drum and through said tube bank vertically supporting said upper drum, a furnace combustion chamber arranged laterally of and adjacent one side of said tube bark and having upright boundary walls disposed in separate planes, said walls including upright wall cooling tubes extending to elevations above said lower drum and having circulatory connections with said drums, one of said boundary walls constituting a wall arranged transversely with respect to said lower drum, means for laterally supporting said walls at a substantially common elevation, means for vertically supporting said walls includin an upright column member externally of and adjacent to wall tubes associated with said transversely arranged wall, and means including a pivoted "vertical support member connecting said column member to said wall tubes of said transversely Number Name Date arranged wall at approximately said elevation of 1,795,357 Allen Mar. 10, 1931 lateral support. 1,802,750 Black Apr. 28, 1931 GLEN J. SCHOESSOW. 1,830,169 Lawrence Nov. 3, 1931 5 1,866,570 Kerr July 12, 1932 REFERENCES CITED 1,972,100 Lucke Sept. 4, 1934 The following references are of record in the 2,1143% Jacobus 1938 file of this patent: 2,223,215 Kunz et al. Nov. 26, 1940 2,231,970 Toomey et al. Feb. 18 1941 UNITED STATES PATENTS 10' 2,254,226, Koch Sept. 2, 1941 Number Name Date 2,267,839 Rehm et al. Dec. 30, 1941 2,276,281 Bailey Mar. 17, 1942 728,996 See May 1903 2295538 Bailey Sept 15 1942 1 634 084 Ruths June 28 1927 2,333,777 Godshalk Nov. 9, 1943 1,779,719 Van Brunt Oct. 28, 1930 

